1. Field of the Invention
The invention relates to a three-plate die-casting tool having a gating system, and to a gating system.
2. Prior Art
Die-casting, which also comprises injection-molding in the broader sense, is known to be a forming method in which an amount of casting material capable of flow, coordinated with the size of the cast components, is introduced into a die-casting tool of a die-casting machine, which tool can be opened and closed.
Known die-casting machines usually have two mounting plates that lie opposite one another and stand vertically, of which one is fixed in place and the other can be driven, in movable manner, parallel to the mounting plate held in fixed manner. A tool half of the die-casting tool is mounted on each of the sides of the mounting plates of the die-casting tool that face one another. Each tool half in turn can consist of multiple tool parts. The two tool halves are divided along a vertical mold parting plane or separation plane. The tool half that is fixed in place is disposed on what is called the gating side, while the movable tool half is situated on the ejector side.
The casting mold formed by the die-casting tool or the tool halves, having a mold cavity that forms the negative contour of the cast component, is filled with casting material capable of flow, particularly with a light material, preferably with a light metal, and shaped. Subsequently, the cast component solidifies, until the cast component can be handled. After the cast component has solidified, it is removed from the mold. For this purpose, the die-casting machine moves the two tool halves away from one another. The cast component remains in the ejector side at first, and is ejected using a separate ejection apparatus.
Furthermore, the die-casting tool comprises what is called the gate or gating system, in order to accommodate the casting material capable of flow that comes from the casting chamber and is accelerated during the casting process and to which pressure is applied, and to pass it into the tool cavity. The gate, particularly its form and connection to the cast component, influences the tool filling process and thereby also the quality of the cast component.
Usually, the gate or the gating system consists of different segments. Thus, the gating system comprises the gating cone, which is also referred to as a gating bar or gating rod, furthermore one or more gating distributor channels, which are also referred to as gating channels or gating spider, and a gating sprue, the cross-section of which is called “ingate” at the entry into the cast component. For the latter, the term connection is also used.
Aside from the aforementioned die-casting tools, three-plate tools are also known. In these three-plate tools, cast component and gating system lie in different tool planes. The two tool halves, in other words the gating-side and the ejector-side half of the tool, which have already been mentioned, are separated from one another by means of an intermediate plate, which exposes a further separation plane during the tool opening movement. Because the die-casting tool can essentially be divided into three modules by means of the intermediate plate, this is referred to as a three-plate tool. The gate or the gating system of the three-plate tool is a gating system that is necessarily self-separating, which is separated from the cast component by means of the opening movement of the three-plate tool. During the opening process, the three-plate tool is first opened in the first separation plane and then in the second separation plane, so that the cast component and the gating system are separated, the latter at least in part.